ES-Series: Electronic safety switching devices with TÜV approval, SIL2 & EU type approval

According to DIN EN 378, plant operators are required to provide pressure monitors, pressure limiters or safety pressure limiters in their machines and plants in order to ensure a safe condition for personell and machine at all times in the event that pressure limit values are unintentionally exceeded in the process.

Conventional devices for pressure limitation often offer only rough, mechanical adjustment options with regard to the switching points and reset values. The pressure measuring cells used have limitations in terms of compatibility with refrigerants.

ZILA GmbH now offers a product family of type-tested, electronically configurable safety switching devices, newly developed from scratch, for use in refrigeration plants and heat pumps as well as in steam boiler and heating systems. The devices convince with their excellent safety characteristics as well as a multitude of expert functions, which save resources during commissioning, daily operation and maintenance over the entire period of plant operation.

Type-tested & TÜV certified electronic safety switching device according to DIN EN 378

The ES series combines several safety functions in a compact anodized aluminum housing: The devices can be used as minimum pressure limiters as well as maximum pressure limiters (type-tested PSH/PSL, PZH/PZL and PZHH/PZLL according to DIN EN 378) and are considered as equipment with safety function in the sense of the Pressure Equipment Directive category IV as well as according to "VdTÜV Druck 100" as pressure limiters of special design. The safety functions of the device are electrically connected in series and thus offer maximum safety.

ES-2x Series specifications and documents

Precise pressure cells with high media compatibility

Electronic pressure measuring cells with a welded stainless steel diaphragm are used to record the system pressure. These ensure media compatibility with a wide range of natural refrigerants and flammable media. R744 (CO2), R219 (propane) and R717 (ammonia) are of particular interest in mechanical and plant engineering. The units of the ES-2x series cover common pressure ranges in subcritical applications as well as in transcritical areas. Apllications up to 500bar are type-tested.

ZILA ES-2x Series product variants and options

Plant operators can select the optimal safety switching device for their application from three product variants (ES-20, ES-21, ES-22), with all variants being SIL2 certified. Depending on which type of safety function must be used according to DIN EN 378, the devices have safety functions of a pressure regulator, pressure cut out, pressure monitor, and a safety pressure limiter individuually or combined in a single housing.

The product series of electronic pressure cut out devices can be expanded into a measurement and control system for machines and plants by expanding the measuring and switching channels. With the measurement channel extension plant operators can monitor up to four pressure circuits simultaneously. For this purpose, specially developed SIL-2-capable pressure transmitters (ZT-S) are connected to the ES device via a secure communication interface. The "ESE" expansion unit developed by ZILA can be connected directly to an ES-2x device to expand the ES-2x device with additional switching channels.

Advanced configuration and precise monitoring of the system pressure

A major advantage of the electronic safety switching device is the comprehensive operating concept. Switching points, switching delays, hysteresis and many other parameters are configured directly on the device or conveniently via Bluetooth using a smartphone app. Thus, switching points can be set to within 0.1 bar of the nominal pressure range. Another special feature is that the integrated test for the correct functionality of the switching points can be carried out at any time without applying system pressure.

Bluetooth, app control and advanced service and diagnostic functions

Plant operators benefit from helpful service and diagnostic functions by using the ZILA ES-2x series. The integrated electronics perform regular self-tests and show measured values, alarms & device status on the integrated display. The electronic safety switching device also acts as a data logger for measurements and performs a leak test with adjustable parameters such as duration, interval or end time. Various measured values, alarms and changes in process conditions are automatically recorded and stored in designated log files by the device.

The features of the ES Series are rounded out by the smartphone app developed specifically for the device. Using the Android app, installers, plant technicians and inspectors can view important device information and transfer the error logs, configuration files and change histories from the device to the Bluetooth-connected smartphone for documentation purposes.